Buggy code:
public final class JsonReader { private final byte [ ] buffer ; private final int length ; private final ServiceLocator locator ; private final char [ ] tmp = new char [ 48 ] ; private int tokenStart ; private int currentIndex = 0 ; private byte last = '<seq2seq4repair_space>' ; public JsonReader ( final byte [ ] buffer , final ServiceLocator locator ) { } public JsonReader ( final byte [ ] buffer , final int length , final ServiceLocator locator ) throws IOException { } public final byte read ( ) throws IOException { } public final byte last ( ) { } public final String readShortValue ( ) throws IOException { } public final int getTokenStart ( ) { } public final int getCurrentIndex ( ) { } public final char [ ] readNumber ( ) { } public final String readSimpleString ( ) throws IOException { } public final char [ ] readSimpleQuote ( ) throws IOException { } public final String readString ( ) throws IOException { } private static int hexToInt ( final byte value ) throws IOException { } private String byteDetails ( final byte c ) { } private boolean wasWhiteSpace ( ) { } public final byte getNextToken ( ) throws IOException { } public final byte moveToNextToken ( ) throws IOException { } public final long positionInStream ( ) { } public final int fillName ( ) throws IOException { if ( ( last ) != '"' ) throw new IOException ( ( ( ( "Expecting<seq2seq4repair_space>\'\"\'<seq2seq4repair_space>at<seq2seq4repair_space>position<seq2seq4repair_space>" + ( positionInStream ( ) ) ) + ".<seq2seq4repair_space>Found<seq2seq4repair_space>" ) + ( ( char ) ( last ) ) ) ) ; tokenStart = currentIndex ; byte c = read ( ) ; long hash = - 2128831035 ; for ( ; c != '"' ; c = read ( ) ) { hash ^= 255 & c ; hash *= 16777619 ; } <START_BUG> if ( ( read ( ) ) != ':' ) <END_BUG> throw new IOException ( ( ( ( "Expecting<seq2seq4repair_space>':'<seq2seq4repair_space>at<seq2seq4repair_space>position<seq2seq4repair_space>" + ( positionInStream ( ) ) ) + ".<seq2seq4repair_space>Found<seq2seq4repair_space>" ) + ( ( char ) ( last ) ) ) ) ; return ( ( int ) ( hash ) ) ; } public final int calcHash ( ) throws IOException { } public final boolean wasLastName ( final String name ) { } public final String getLastName ( ) throws IOException { } private byte skipString ( ) throws IOException { } public final byte skip ( ) throws IOException { } public final String readNext ( ) throws IOException { } public final byte [ ] readBase64 ( ) throws IOException { } public static interface ReadObject < T > { T read ( final JsonReader reader ) throws IOException { } } public static interface ReadJsonObject < T extends JsonObject > { T deserialize ( final JsonReader reader , final ServiceLocator locator ) throws IOException { } } public final boolean wasNull ( ) throws IOException { } public final boolean wasTrue ( ) throws IOException { } public final boolean wasFalse ( ) throws IOException { } public final < T > ArrayList < T > deserializeCollectionWithGet ( final JsonReader . ReadObject < T > readObject ) throws IOException { } public final < T > ArrayList < T > deserializeCollectionWithMove ( final JsonReader . ReadObject < T > readObject ) throws IOException { } public final < T > void deserializeCollectionWithGet ( final JsonReader . ReadObject < T > readObject , final Collection < T > res ) throws IOException { } public final < T > void deserializeCollectionWithMove ( final JsonReader . ReadObject < T > readObject , final Collection < T > res ) throws IOException { } public final < T > ArrayList < T > deserializeNullableCollectionWithGet ( final JsonReader . ReadObject < T > readObject ) throws IOException { } public final < T > ArrayList < T > deserializeNullableCollectionWithMove ( final JsonReader . ReadObject < T > readObject ) throws IOException { } public final < T > void deserializeNullableCollectionWithGet ( final JsonReader . ReadObject < T > readObject , final Collection < T > res ) throws IOException { } public final < T > void deserializeNullableCollectionWithMove ( final JsonReader . ReadObject < T > readObject , final Collection < T > res ) throws IOException { } public final < T extends JsonObject > ArrayList < T > deserializeCollection ( final JsonReader . ReadJsonObject < T > readObject ) throws IOException { } public final < T extends JsonObject > void deserializeCollection ( final JsonReader . ReadJsonObject < T > readObject , final Collection < T > res ) throws IOException { } public final < T extends JsonObject > ArrayList < T > deserializeNullableCollection ( final JsonReader . ReadJsonObject < T > readObject ) throws IOException { } public final < T extends JsonObject > void deserializeNullableCollection ( final JsonReader . ReadJsonObject < T > readObject , final Collection < T > res ) throws IOException { } }

Fix:
if ( ( getNextToken ( ) ) != ':' )